I could also place the screws vertically, and belay off the lower screw. that would prevent extension if the bottom screw ripped.

I typically try to offset my screws when using them as an anchor, setting them in a diagonal line rather than side-by-side or vertical. I don't like side-by-side since ice often fractures horizontally, and I don't like vertical since it adds some clustering and forces you to put 2 screws on the exact same feature.

Edit: Dammit, rangerrob said that already. Apparently, the ridiculous amount of money I have spent on my education still hasn't taught me how to read.